A structured light is a lighting apparatus by which lighting pattern is with a specified feature, structure or form over one assigned surface or object. It has been applied to many categories for many purposes, mainly the function is to enhance the contrast of object with respect to the others in environment such that identification or recognition can be greatly achieved. With increasing development of optical technologies, the structured light is designed to have a linear pattern, a planar pattern, a grid pattern or even a more complicated light pattern. Consequently, the structured light can be applied to many emergent fields such as 3D contour regeneration technologies, distance measurement technologies, anti-counterfeiting recognition technologies, motion sensitive technologies, novel appearance designs and associated applications. By using the structured light, the conventional warning signs can be extensively applied to medical applications or biomedical applications that require pollution-free environments. In other words, the importance of the structured light is gradually increased and the associated technologies are widely developed.
Generally, a structured light generation unit is used for generating a structured light. When the structured light is projected on an object, a structured light pattern is formed on a surface of the object. The structured light pattern on the surface of the object is an important identification feature for judging the spatial information. However, regardless of whether the structured light pattern is a linear pattern, a planar pattern or a grid pattern, the density and/or the number of the structured light patterns are still insufficient or the corresponding projection area is insufficient in many applications once a higher resolution is targeted. Consequently, the structured light pattern cannot be used in the subsequent process of precisely calculating the spatial information. Moreover, in case that the projected contents of the structured light pattern are not diversified, the applications of the structured light pattern are limited. In other words, the optical device for generating the structured light still needs to be improved.